Outcome of adolescent patients with acute myeloid leukemia treated with pediatric protocols.

As past studies of adolescent and young adults (AYA) with acute myeloid leukemia (AML) reported conflicting results, we conducted a retrospective analysis using data from three Japanese pediatric AML studies. Among the 782 patients with de novo AML, 44 were classified as AYA (age ≥15 years at diagnosis), 164 as infants (0-1 year), 413 as younger children (2-11 years), and 161 as older children (12-14 years). While the 5-year event-free survival rate of AYA was not different among the groups, the five-year survival rate (54.7 %) was significantly lower than that of the other three groups (P = 0.019): 68.7 % for infants, 73.2 % for younger children, and 75.5 % for older children. No difference in the 5-year cumulative incidence of relapse was observed, but treatment-related death (TRD) of AYA was significantly higher (29.4 %) than that in infants (14.8 %), younger children (10.2 %), and older children (13.8 %). Multivariate analysis showed age ≥15 years old at diagnosis was associated with both poor survival rate and high TRD. Adolescents with AML had inferior survival due to a higher incidence of TRD, especially after failure of initial frontline treatment.